The total of the interest and interest rate swap payments that become due and payable on a given date, that are exempt from tax under sub‑paragraphs (1), (3) and (4), must not exceed an amount computed by the following formula:where —
(a) A is the portion of the loan mentioned in sub‑paragraph (2) that has been drawn down as at that date;
(b) B is the total of the loan under the Loan Agreement that has been drawn down as at that date;
(c) C is the interest amount in sub-paragraph (1) that becomes due and payable on that date; and
(d) D is the total of the interest rate swap payments in sub‑paragraphs (3) and (4) that become due and payable on that date.